Adjustable hone



oct 19, 194s. J. J'. PALOTCE 2,332,463

ADJUSTABLE HoNE Filed Deo. 21, 1942' on its exterior orgrinding surface.

Patented Oct. 19, 1943 UNITED STATES y PATENT OFFICE ADJUSTABLE HONE John J. Paiotce, Youngstown, Ohio Application December 21, 1942, Serial No. 469,714

16 Claims.

This invention relates to adjustable abrasive hones, the present invention being an improvement upon the hone disclosed in my U. S. Letters Patent #2,269,378, dated January 6, 1942.

In my aforesaidv Patent #2,269,378 an adjustable abrasive cylindrical stone hone was disclosed having a relatively small diameter. said hone being particularly adapted for grinding, machining, finishing, polishing, or boring, cylindrical bearings of relatively small diameter, such as crank-shaft bearings, connecting-rnd bearings, wrist pin bearings, main bearings, or the like. Said hone consisted of a spindle carrying an annular series of radially shiftable segmental stone holders each carrying a carborundu'm hone section, said holders and hones when fully contracted around the spindle forming an unbroken cylindrical grinding surface having .spiral grooves The said holders and spindle were provided with complemental tapered surfaces, means boing also provided for shifting the spindle axially of the holders to eiiect an expansion or contraction of the hone with respect to the spindle to vary the effective diameter thereof, said hone having means holders |-from bulging outwardly when the spindle is shifted to expand the holders with respect to the spindle.

A still further object of the invention is to provide a novel centering means for the hone holders at the inner end of the hone, said means infor yieldably maintaining the tapered surfaces of the holders and spindle in close contact while permitting shifting of the spindle, said yieldable means also preventing the holders from bulging outwardly when the spindle was shifted to expand the holders with respect thereto. Said hone was also provided with an indicator scale for visibly indicating the diameter to which the hone was adjusted;- and the spindle was provided with centering means at each end for the hone holders, whereby the hone assembly might be accurately ground into truly cylindrical shape.

One object` of my present invention is to provide an improved hone of the above type. in which the centering means for the hone holders at the outer end of the hone is disposed entirely within the outer ends of the hone holders, to permit end or bottom grinding of bores or the like, such as when the hone is used to grind the walls of a bore which is closed at its bottom end and the grinding is to be effected entirely down to the said bottom or closed endof the bore.

. Another object of the invention is to provide an adjustable tapered hone for use in grinding or polishing tapered bores, or for machining, finishng or boring said tapered bores.

A furtherV object of the invention is to provide novel improved means for yieldably maintaining the tapered surfaces of the holders and 'spindle cluding a threaded nut-like member which is rotatably and axially movable with respect to the spindle, to shift the spindle with respect to the hone holders and thereby effect expansion and contraction of the hone, said member carrying an internal annular gear adapted to be engage-d by a pinion mounted-on a hand crank removablyy Journaled in a bearing carried by the spindle, so that the crank may be readily inserted into place in said bearing after a grinding operation is completed, the bearing being readily and always accessible at said inner end of the hone, whereby the crank when rotated will cause contraction of the hone within the bore to facilitate removal of the hone therefrom.

. Other minor objects of the inventionk will be hereinafter set forth. I will explain the invention with reference to the accompanying drawings which illustrate several practical embodiments thereof, to enable othersy familiar with the art to adopt and use the same; and will summarize in the claims the novel features of construction, and novel combinations of parts, ,for which protection is desired.

In said drawings:

Fig. 1 is a longitudinal section through an advjustable stone hone embodying myinvention.

Fig. 2 is a reduced side elevation of one form Aof my novel hone adaptedfor grinding cylindrical bores, or the like.

Fig. 3 is a reduced elevation of a nodified form of hone adaptedfor .grinding tapered bores, or the like.

Fig. 4 is an enlarged encl elevation'of the hone looking at the outer end of the' hone shown in the hone holders with hone section, detached from* the assembly.

Fig. 9 is anend elevation of the hone holder into contact and for yieldably preventing the shown in Fig- 3 Fig. is a bottom plan view of the holder shown in Fig. 8.

Fig. 11 is a transverse section on the line II-II,'Flg. 12.

Fig. 12 is a section on the line I2-I2, Fig. 1l.

As shown, my novel hone preferably comprises a relatively long tubular pilot spindle I of substantially the same length as the desired hone abrasive surface, said spindle I having a hexagonal tapered enlargement Ia .(Figs. 1 and 5) at its cuter end, said taper flaring outwardly towards the end of the spindle. Intermediate the ends of the spindle are one or more similar hexagonal tapered enlargements Ib (Figs. 1 and 6) having the same slope or taper asc enlargement Ia and enlarging in the same direction. Adjacent the inner end of the spindle I is a similar hexagonal tapered enlargement Ic having the same llope or taper as the enlargements la, Ib and likewise enlarging in the same direction.

Beyond the enlargement Ic the tubular spindle I is internally threaded as at Id to receive the threaded shank 2a of handle 2 which may be engaged with a vise (not shown) or used for power rotation of the hone, said handle 2 being of non-circular cross-section, as shown. The end of spindle I is likewise externally threaded as at Ie, and on the threaded end I e is u tubular hand nut 3 having a tapped inner wall 3a engaging threads Ie and having a knurled outer wall 3b and having an end wall 3c of Vconical shape, said wall 3c enlarging outwardly and forwardly of the hone as shown in Fig. 1, the end of tubular nut 3 adjacent handle 2 being open. In the outer wall 3b of nut 3 are a series of holes 3d adapted to receive a tool to eec't rotation of nut 3 on spindle I when handle 2 is maintained against rotation, or .the knurled nut 3 may be rotated by hand to shift the nut axially of the spindle I.

ln the opposite end of tubular spindle I is an enlarged axial bore If (Figs. 1 and 5) of substantial length adapted to slidably receive a tubular member 4 housing a bolt 5 having a head 5a slidable within the outer end of tube 4, the shankof bolt 5 passing through a perforation in the inner end 4a of tube 4, and engaging a tapped bore in a member la ilxedly mounted in the bore of spindle I adjacent the end of tube 4. Within tube 4 disposed between the head 5a of bolt 5 and the end wall 4a of the tube is a coiled spring 6 under compression and normally urging the tube 4 inwardly of the spindle bore If. At the cuter end of tube 4 is an annular conical lflange 4b opposed to the conical recess 3c in the tubular nut 3 and for the purpose hereinafter described. In the outer end of head 5a of bolt 5 is a diametrical slot 5c forengagement with a screw driver or other tool whereby the bolt ma be threaded into the member 1g.

The six faces of the tapered enlargements la, Ib, Ic of the spindle are adapted to slidably support six metallic blade holders 8, shown more particularly in Figs. 1, 5, 6, 8, 9 and 10, said holders Iextending substantially the length of spindle I and extending beyond said extensions la and Ic; and said holders are mounted around the spindle and are of such Width that the sides thereof will abut when the holders 8 are fully retracted. Each holder 8 is provided with spaced undercut recesses 8a (Figs. 5 and 6) holding thereon an abrasive covering of carborundum or other honing material 9 which is preferably cast onto the holder, said hones 9 extending outwardly beyond the faces of the holders 8 and having an arcuate outer periphery whereby the peripherles of all the six hones 8 when their holders 8 are in retracted position will together form a cylindrical grinding surface in which the sides of the hones 8 in adjacent holders contact squarely, the side walls of the holders and hones of adjacent sections slightly separating as the hone is expanded.

On the underside of each holder 8 adjacent its outer end is a tapered surface 8b conforming with the taper of the enlargement Ia of spindle I; and intermediate the ends of each holder 8 are one or more tapered surfaces 8c conforming with the taper of the enlargements Ib of spindle I; and adjacent the inner end of each holder 8 is a tapered surface 8d conforming with the taper of the enlargement Ic of spindle I. Each of the tapered surfaces 8b, 8c and 8d are of less length than their corresponding surfaces Ia, Ib and Ic. On the undersides of the holders 8 coextensive therewith are axially disposed combined reinforcing ribs and guides 8e engaging corresponding longitudinal slots Ih (Figs. 5 and 6) in each of the tapered surfaces Ia, Ib and Ic whereby each of the holders 8 may be moved radially inwardly or outwardly of spindle I but are prevented from lateral movement thereon.

At the inner end of each holder 8 is a projecting lug 8f tapered as at 8g and entering the conical recess 3c in the nut 3 as shown in Fig. 1. At the outer end of each holder 8 is a recess 8h inthe underside of the holder forming a shoulder 87' (Fig. 1) adapted to be engaged by the conical flange 4b of tube (l as shown in Fig. 1, whereby the flange 4b is housed entirely within the outer ends of the holders 8 to permit end cr bottom grinding, such as when the hone is being used to grind or polish the walls of a bore having a bottom, and the grinding or polishing is to be eected entirely down to the said bottom of the bore. By the above construction the ends cf the holders 8'are maintained upon the spindle I, the same being confined between the nut 3 and flange 4b. The distance between the nut 3 and ange 4b however is variable, owing to the provision of the spring 6 interposed between the bolt head 5a and the inner end of tube 4, and thus the conical holder engaging faces of the nut 3 and flange 4b are permitted to engage the correspondingly shaped ends of the holders in all retracted or projected positions of the holders 8 to thereby yieldably maintain the tapered surfaces 8b and 8d of the holders 8 in close contact with their corresponding tapered surfaces Ia and Ic of spindle I for any axially adjusted position of spindle I with respect to the holders 8.

In order to prevent outward bulging of the relatively long holders 8 during operation or during axial adjustment of the spindle, the guide 8e of each holder 8 is provided just beyond the larger end of each intermediate spindle enlargement Ib with an undercut recess 8k (Fig. 1) having a lug 8m on its wall adjacent enlargement lfb adapted to form a seat for a split annular spring ring I8 (Figs. 1 and 6) which when so seated yieldably contracts the assembly of holders 8 while permitting expansion thereof. In the adjacent end of each enlargement Ib is a seat Ia: adapted to temporarily hold the springs I0 in slightly expanded position as shown in dotted lines in Fig. 1, said seats Ia: being adapted to hold the springs I0 for positioning same into the seats 8m of the holders 8 when assembling 'the holders on the spindle. I. During such assembly, with nut 3 first removed, the holders 8 are positioned on their respective enlargements Ia, Ib, Ic of spindle I with the recesses 8k disposed to the right (Fig. 1) of the seats Ia: which are temporarily carrying the springs I0. The holdersa are then shifted together to the left into position shown in Fig. 1, and while the recesses 8k pass over the seats la', the lugs 8m take'up the split annular rings Il) from their temporary seats lx, the springs seating themselves upon said lugs 8m upon which same are retained until the holders 8 lare disassembled from the spindle by reversing the above procedure, i. e., by moving the holders so that the recesses 8k pass to the right (Fig. 1) over the seats Irc, at which time the split annular rings I are again deposited upon Vtheir said temporary seats Ix.

In assembling the hone, the nut 3 would firstbe removed from spindle I sufficiently to permit the six hone holders 8 to be placed into their respective positions onthe spindle with the guides 8e respectively engaging the slots Ih in the tapered enlargements la, Iband Ic. Inso placing the holders the recesses 8k would be disposed to the right (Fig. 1) of their related temporary seats I1: (above mentioned) carrying temporarily the split ring Ill, and the six holders 8 then shifted to the left (Fig. 1) so as to pick up the rings III. The nut 3 would then bel applied to the spindle I and the nut 3 shifted on the spindle suiiiciently to engage the tapered ends 8b of the holders 8 in the conical recess 3c of nut 3 and bring the shoulders 87' of the holders 8 into contact with the conical flange 4b of tube 4, the shifting of the nut 3 on spindle I being effected either manually or by 'using a tool engaging the holes 3d in the nut 3 while holding the handle 2 stationary. Further shifting of the nut 3 to the left (Fig. 1) will move the spindle I axially with respectto the assembled holders 8 (towards the right, Fig. 1) and the sliding movement of the tapered portions la, Ibv and'Ic of spindle I on their related tapered portions 8b, 8c and 8d of the respective holders 8 will cause the holders to move radially outwardly while the guides 8e are retained in their respective guide slots Ih in the tapered portions of the spindle I, said holders separating slightly during the expanding movement. Since flange 4b is yieldably connected with the spindle I the nut 3 and flange 4b will of the holders 8 will permit the holders to move radially outwardly while at the same time the.

springs 6 will cause the collars to yieldably maintain the tapered portions 8b, 8d of the holders 8 in contact with their corresponding tapered portions of the enlargements la and lc, thus forming a relatively rigid assembly for any axial adjustment of the spindle.' .During the expansion and vcontraction of the holders the split annular rings I0 merely yield to such movement.

When the parts are thus assembled the hone may be placed in a power grinding machine centered by conical recesses (not Ashown) in the outer 'ends of the bolt head 5a and handle 2,y

and the peripheries of all of the hones 9 may be ground accurately to form a true cylindrical surface concentric with the axis of the hone 0r spindle as shown in Fig. 2, or to form a tapered surface as shown in Fig. 3, the larger end of the taper being disposed adjacent the handle 2- (Fig. 3). As shown in Fig. 9 the peripheries of the hones` 9 of the holders may be provided with lgrooves 9a which, when the holders are fully retracted, form interconnecting spiral grooves providing recesses which will permit accumulations of cuttings and grinding to pass off to one side, which cuttings if not removed might build up the effective diameter of the hone and throw same oficenter. When grinding relatively long bores the hand end of the hone may become completely housed within the bore and hence it is then difilcult to manipulate the nut 3 to contract the hone sutilcient with respect to the walls of the bore, to permit ready removal thereof. In order to facilitate ready retraction of the hone from the same end of the bore that it entered, I provide, at the end of the outer wall 3b of hollow nut 3, an internal annular gear 3x (Figs. l and 7) extending entirely around the inner circumference of said wall 3b. Within hollow nut 3 is an annular bearing plate II having an annular series of holes IIa therein, for the purpose hereinafter described, plate II being disposed transversely of the axis of spindle I and the pitch circle of the holes Ia being of less diameter than the gear 3x. Plate II is provided with an annular hub portion IIb overlying the end of spindle I, as shown in Fig. 1, the outer end of rhub portion I Ib being flanged downwardly as atl Ic and having an axial opening therein adapted to lit over the threaded portion 2a, of handle 2 and to seat squarely against the shoulder formed between threaded portion 2a and main portion of handle 2, as shown in Fig. 1, so as to be confined in position against said shoulder by the endof the spindle I. The flange llc of plate Il is provided with diametrically disposed lugs lid '(Fgs. 1, 1l and 12) adapted to enter notches Iy formed in the adjacent end of spindle I so that when the spindle, handle and plate are assembled the lugs IId engaged in the notches Ig/ will prevent the plate Il from rotating with respect tov vthe spindle I or handle 2.

A removable hand crank I2 is also provided (Figs. 1 and 7) having an elongated pinion I2a thereon adjacent its inner end and having a crank (not shown) adjacent its outer end. The inner end of the crank I2 is adapted' to bejournaled in any of the holes IIa in plate II so as to bring pinion I2a into mesh with internal annular gear 3a: carried by nut 3, as indicated in Fig. 1,. Since plate II is non-rotatable with respect to the handle 2, as soon as the hand crank I2, when thus engaged, is rotated it is obvious that nut 3 may be correspondingly rotated in a direction to contact the hone within the bore to permit ready removal thereof in the opposite direction from which hone entered the bore, even though the handle end of the hone may have been entered into and be'housed within the bore suiciently to coverl the nut 3 so ythat said nut cannot be manipulated by a tool engaged in the holes 3d of the nut, or manually manipulated by grasp of the hand.

If desired a series of interchangeable plates II may be provided in which the distance between the main body of plate II and the ange I Ia differ, in order that one of said plates I I may be utilized for operation of gear 3m by hand crank I2 irrespective of the position of the nut 3 upon the threaded end Ie of spindle I, i. e., irrespective of the relative amounts of expansion of the hone from its normal retracted position, it being obvious that when nut I is disposed adjacent the inner end of threads le of the spindie the gear Iz of the nut would be disposed at the opposite or left hand side of the plate Ii (Fig. l) and hence pinion |2a of crank l2 would then not be engageable with the gear 3m. An interchangeable plate Il having` a relatively long hub portion lib however, if replaced for the plate ii shown in Fig. l, would again restore the parte to the same relative positions shown in Fig. 1 in which the gear 3x is disposed at the right hand side of the main portion of plate il in which the bearing holes I `la are provided.

As shown in Figs. 2 and 3, means are provided for visually indicating to the operator the diameter to which the hone is adjusted. The periphery of nut 3 adjacent the end of hone 8 is provided with an annular graduated scale 3s cooperating with any of the edges of the hone sections 9, so that when the nut 3 is rotated relative to the spindle, the reading of the scale 3s with respect to the same edge of the hone section, will directly indicate the change in diameter of the hone without necessitating the use of calipers or other extraneous measuring instruments. The scale of the calibrations may be such as to indicate any desired unit, such as one division equalling .001 of an inch.

I do not limit my invention to the exact form shown in the drawings, for obviously changes may be made therein within the scope of the claims; and instead of using six holders and hones as shown in the drawings, amore or less number may be similarly used as desired.

I claim:

1. An adjustable hone, comprising a. spindle provided with spaced polygonal enlargements having their outer faces axially aligned and tapering at the same angle and in the same direction; a plurality of longitudinally disposed hone holders around the spindle embracing the enlargements .and having correspondingly tapered inner faces seated upon the aligned outer faces of the enlargements; segmental hones in the respective holders adapted when the holders are contracted to form an unbroken abrasive surface around the spindle; extensions at one end of the holders having outer faces inclined towards the spindle: a nut axially movably mounted on the adjacentend of said spindle and having a frusto-conical recess receiving the said extensions; the opposite ends of said holders having undercut recesses in their undersides together forming an internal annular undercut. shoulder spaced inwardly from the said end of the holders; and a yieldable member within the opposite end of the holders slidably mounted on the spindle and having a head housed within the holders and the adjacent end of the hones and provided with a frusta-conical recess engaging the said undercut annular shoulder, whereby when the holders are shifted by the nut axially of the spindle to adjust the holders radially thereof said nut and head will' yieldably retain the holders on the spindle.

2. In a hone as set forth in claim l, said segmental hones forming a frustum of a cone largest in diameter adjacent said nut.

3. An adjustable hone, comprising a spindle provided with spaced polygonal enlargements having their outer faces axially aligned and tapering at the same angle and in the same direction; a Vplurality of longitudinally disposed hone holders around the spindle embracing the enlargements and having correspondingly tapered inner faces seated upon the .aligned outer faces of the enlargements; segmental hones in the respective holders adapted when the holders are contracted to form an unbroken abrasive surface around the spindle; extensions at one end of the holders having outer faces inclined towards the spindle a nut axially movably mountedon the adjacent end of said spindle and having a frusto-conical recess receiving the said extensions; the opposite ends of said holders having undercut recesses in their undersides together forming an internal annular undercut shoulder spaced from the said end of the holders: and a yieldable member within the opposite end of the holders slidably mounted on the spindle and having a, head provided with a frustoconical recess engaging the said undercut annular shoulder, whereby when the holders. are shifted by the nut axiallyof the spindle to adjust the holders radially thereof said nut and head will yieldably retain the holders on the spindle, longitudinally disposed ribs on the undersides of the holders engaging corresponding slots in the tapered faces of the spindle enlargements, said ribs having recesses in their inner edges adjacent intermediate enlargements and provided with lateral projections within said recesses;` and split spring rings around the spindle within the respective recesses and seated upon the said respective prjections.

4. In combination with a hone as set forth in claim l longitudinally disposed guide ribs on the undersides of the holders engaging corresponding slots in the tapered faces of the spindle enlargen'fientsrl` said ribs having recesses in their inner edges adjacent the larger ends of the intermediate enlargements and provided with lateral projections within the said recesses; and split spring rings around the Spindle normally seated upon the said projections in the respective recesses; said enlargements having annular shoulders in their larger ends adapted to likewise hold the said rings, whereby when the rings are seated on said projections and the holders shifted to move the recesses across said annular shoulders of the enlargements, the rings will be transferred to said shoulders, and whereby when the holders are again moved in the opposite direction to move their recesses across the shoulders the rings will be again transferred. to said projections in the recesses.

5. An adjustable hone, comprising a spindle lprovided with spaced polygonal enlargements having their outer faces axially aligned and tapering at the same angle and in the same direction; a plurality of longitudinally disposed hone holders around the spindle embracing the spaced enlargements and having correspondingly tapered inner faces seated upon the alined outer faces of the enlargements; segmental hones in the respective holders adapted when the holders are contracted to form an unbroken abrasive surface around the spindle; extensions at one end of the holders having outer faces inclined towards the spindle; a nut axially movably mounted on the adjacent end of said spindle and having a conical recess receiving the said extensions; the opposite ends of said holders having undercut recesses in their undersides together forming an internal annular undercut shoulder spaced inwardly from the said end of the holders: said spindle having an axial bore in its end opposite from the nut; a member slidably engaging the bore;

means yieldably urging the member inwardly oi' said bore; said member having a conical head exterior o'i' the bore and disposed within the adjacent end ofv the holders and hone segments and engaging said undercut shoulder, whereby when the spindle is moved axially of the nut the contacting tapered faces of the holders and spindle will adjust the holders radially of the spindle while the said nut and head will yieldably retain the holders on the spindle.

6. In combination with a hone as set forth in claim 5, a bearing xedly mounted on the spindie; and a removable rotatable tool adapted to be journaled in the bearing and to engage the nut for rotating the said nut.

7. An adjustable hone, comprising, a spindle provided with spaced polygonal enlargements having their outer faces axially aligned and tapering at the same angle and in the same direc-y tion; a plurality of longitudinally disposed hone holders around the spindle embracing the enlargements and having correspondingly tapered inner faces seated upon the aligned outer faces of the enlargements; segmental hones in the respective holders adapted when the holders are contracted to form an unbroken abrasive sur` face around the spindle; extensions at one end of the holders having outer faces inclined towards yieldably retain theJ holders on the spindle; said nut being hollow and open at its outer end; and,

said nut rotating means comprising a plate nonrotatably mounted on the spindle and, entering the open end oi' the nut, and having a bearing the spindle; a nut axially movably mounted on the adjacent end of said spindle and having a frusto-conical recess receiving the said extensions; the opposite ends of said holders having f undercut recesses in their undersides together forming an internal annular undercut shoulder spaced inwardly from the said end of the holders; a yieldable member within the opposite end of the holders slidably mounted on the spindle and having a head housed within the holders and the adjacent end of the hones and provided with a frusto-conical recess engaging the said undercut annular shoulder, whereby when the shoulders are shifted by the nut axially of the spindle to adjust the holders radially thereof said nut and head will yieldably retain the holders on the spindle; a plate .non-rotatably mounted on the spindle adjacent the nut and having a bearing hole therein; an annular gear carried by the nut;

` a removable hand crank rod adapted to be centered in the hole in the plate, and a pinion mounted on the crank rod adapted to engage the said gear when the crank rod is thus centered.

8. An adjustable hone, comprising a `spindle provided with spaced polygonal enlargements having their outer faces axially aligned and tapering at the same angle and in-the same direction; a plurality of longitudinally disposed hone holders around the spindle embracing the enlargements and having correspondingly. tapered inner faces seated upon the aligned outer faces of the enlargements; segmental hones in the respective holders adapted when the holders are contracted to form an unbroken abrasive surface around the spindle; extensions at one end of the holders having outer faces inclined towards the spindle; a nut axially movably mounted on-the adjacent end of said spindle and having a frustoconical recess receiving the said extensions; the opposite ends of said holders having undercut recesses in their undersides together forming an internal annular undercut shoulder spaced inwardly from the said end of the holders; a yieldable member within the opposite end of the holders slidably mounted on the spindle and having a head housed withinv the holders and the adjacent end of the hones and provided with a frusto-conhole therein; an annular gear Within the nut ad- 'jacent its open end; a removable hand crank rod adapted to be entered into the open end of the nut and to be journaled in the said hole, and a pinion mounted on the crankrod adapted to en.. gage the said gear when the crank rod is thus journaled.

9. An adjustable hone, comprising a spindle provided with spaced polygonal enlargements having their outer faces axially aligned and tapering at the same angle and in the same direction; a plurality of longitudinally disposed hone holders around the spindle embracingv the enlargements and having correspondingly tapered inner faces seated upon the aligned outer faces of the enlargements; segmental hones in the respective holders adapted when the holders are contracted to form an unbroken abrasive surface around the spindle; extensions at one end ofthe holders having outer faces inclined towards the spindle; a nut axially movably mounted on the adjacent end of said spindle and having aV frustoconical recess receiving the said extensions; the opposite ends of said holders having undercut recesses in .their undersides together forming an inl holders radially thereof said nut and head will yieldably retainthe holders on the spindle; said spindle having an axial bore in its end opposite from the nut; the adjacent ends of said holders having undercut recesses in their undersidestoygether forming an internal annular undercut shoulder spaced inwardly from the said end of the holders and constituting said surfaces inclined towards the axis of the spindle; said yieldable member slidably engaging the bore; means yieldably urging the member inwardly of the bore; and said member having a frusto-conical head exterior of the bore housed Within the adjafaces inclined towards the axis of the spindle; a

nut axially movably mounted on the adjacentend of said spindle and having a conical recess receiving the said extensions; the opposite ends of the holders having surfaces inclined towards the axis of the spindle; a yieldable member adjacent said opposite end of the holders slidably engaging the spindle and having a conical recess receiving the adjacent inclined surfaces of the holders, whereby when the holders are shifted by the nut axially of the spindle to adjust the holders radially thereof the said nut and member will yieldably retain the holders on the spindle; longitudinally disposed guide ribs on the undersides of the holders engaging corresponding slots in the tapered faces of the spindle enlargements, said ribs having recesses in their inner edges adjacent intermediate enlargements and provided with lateral projections within said recesses; and splitI spring rings around the spindleseated on the said projections within the respective recesses.

11. An adjustable honefcomprising a spindle provided with spaced polygonal enlargements having their outer faces tapering at the same angle and in the same direction, the corresponding faces of the spaced enlargements being axially aligned; a plurality of longitudinally disposed hone holders around the spindle having correspondingly tapered inner faces seated upon the respective aligned faces of the enlargements; segmental hones in the respective holders; extensions at one end of the holders having their outer faces inclined towards the axis of the spindle; a nut axially movably mounted on the adjacent end of said spindle and having a conical recess receiving the said extensions; the opposite ends of the holders having surfaces inclined towards the axis of the spindle; a yieldable member adjacent said opposite end of the holders slidably engaging the spindle and having a conical recess receiving the adjacent inclined surfaces of the holders, whereby when the holders are shifted by the nut axially of the spindle to adjust the holders radially thereof the said nut and member will yieldably retain the holders on the spindle; longitudinally disposed guide ribs on the undersides of the holders engaging corresponding slots in the tapered faces of the spindle enlargements, said ribs having recesses in their inner edges adjacent the larger ends of the intermediate enlargements and provided with lateral projections within the said recesses; and split spring rings around the spindle normally seated upon the said projections in the respective recesses; said enlargements having annular shoulders in their larger ends adapted to likewise hold the said rings, whereby when the rings are seated on said projections and the holders shifted to move the recesses across said annular shoulders of the enlargements, the rings will be transferred to said shoulders, and whereby when the holders are again moved in the opposite direction to move the recesses across the shoulders the rings will be again transferred to saidprojections in the recesses.

12. In an adjustable hone, a spindle; a plurality of longitudinally disposed hone holders movably mounted around the spindle: a nut on said spindle engaging one end of said holders; means for moving the holders radially of the spindle when shifted by the nut on the spindle; a plate non-rotatably mounted on the spindle adjacent the nut and having a hole therein; an annular gear carried by the nut, a removable hand crank rod adapted to be centered in the hole, and a pinion on the crank rod adapted to engage the said gear when the crank rod is thus centered, whereby the nut may be rotated thereby.

13. In a hone as set forth in claim 12,'said nut being hollow and open at its outer end: said plate entering the open end of the nut; and said annular gear being disposed within the nut adjacent its open end.

14. In an adjustable hone, a spindle provided with spaced polygonal enlargements having their outer faces tapering at the same angle to the spindle axis and in the same direction, the corresponding faces of the spaced enlargements being axially aligned; a plurality of longitudinally disposed hone holders around the spindle having correspondingly tapered inner faces seated upon the corresponding outer faces of the spaced aligned enlargements; means for shifting the holders on the enlargements to vary the diameter of the hone; means for yieldably maintainking the ends of the holders in engagement with the outermost enlargements; longitudinally disposed ribs onl the undersides of the holders engaging corresponding slots in the tapered faces of the enlargements, said ribs having recesses in their inner edges adjacent intermediate enlargements and provided with lateral projections within said recesses; and split rings around the spindle within the respective recesses and seated upon the said respective projections to yieldably maintain the holders in way of the intermediate enlargements from bulging outwardly while permittingradial adjustment of the holders.

l5. In a hone as set forth in claim 14, said recesses in the ribs being disposed adjacent the larger ends of the intermediate enlargements; said enlargements having annular shoulders in their larger ends adapted to temporarily hold said rings, whereby when the rings are seated on said projections of the recesses and the holders shifted to move the recesses across said annular shoulders of the enlargements, the rings will be transferred to said shoulders, and whereby when the holders are again moved in the opposite direction to move the recesses across the shoulders, the rings will be again transferred to said projections.

16. An adjustable hone, comprising a spindle provided with spaced polygonal enlargements having their outer faces tapering at the same angle and in the same direction, the corresponding faces of the spaced enlargements being axially aligned; a. plurality of longitudinally disposed hone holders around the spindle having correspondingly tapered inner faces seated upon the respective aligned faces of the enlargements; segmental hones in the respective holders; extensions at one end of the holders having their outer faces inclined towards the axis of the spindle; a nut axially movably mounted on the adjacent end of said spindle and having a frusto-conical recess receiving the said extensions; the opposite ends of the holders having surfaces maimed towards the axis of the'spindle; a yieldable member adjacent said opposite end of the holders slidably engaging the spindle and having a truste-conical recess receiving the adjacent inclined surfaces of the holders, whereby when the holders are shifted by the nut axially of the spindle to adjust the holders radially thereof the said nut and member will yieldably retain the holders on the spindle; a bearing iixedly mounted on the spindle; and a removable rotatable tool adapted to be journaled in the bearing and to engage the nut for rotating the' said nut.

JOHN J. PALOTCE. 

